Our pest repeller adopts dual-chip ultrasonic technology to efficiently drive pests away. The effective coverage area is about 800 to 1200 square feet,- It uses ultrasonic frequency (22-65Khz) sound waves to drive pest away and takes 3-4 weeks to make effect Wide Coverage Area: Ultrasonic Pest Repeller can be used in various places, such as Bedrooms, Bathrooms, Garages, Kitchens, Offices, Warehouses Easy To Use, Plug & Play: You can simply plug an electronic pest controller into a wall outlet without any tools.This ultrasonic rat repellent is safe for humans and pets.No poisons, chemicals, traps and killings. The pest repeller are 100% safe and harmless to humans, children and pets. It is a physical method that removes pests, is non-toxic, and environmentally friendly.